It may appear like snow at first glance, but it certainly moves and feels more like soap suds. What’s covering the Manzanilla Coast, you may ask? Sea foam, in abundant quantities, is now blowing onto the Manzanilla-Mayaro Road.
Sea foam is a regular feature of coastlines generally after heavy rainfall, as organic matter and runoff pollutants interact in the ocean, naturally producing bubbles. When there are strong winds at the ocean’s surface that agitate seas, these bubbles become sea foam and build on the coastlines.
According to acting director of the Institute of Marine Affairs (IMA), Dr Rahanna Juman, this is not uncommon on Trinidad’s eastern coast.
“Seawater contains several constituents such as dissolved salts, proteins, fats, dead algae, detergents and other land-based pollutants, and pieces of organic matter. If this water was placed in a small receptacle such as a drinking glass and shaken, small bubbles will form on the surface of the liquid. Sea foam forms in this way—but on a much grander scale —when the ocean is agitated by wind and waves.”
The IMA added, “The East Coast receives land-based runoff from many rivers along that coast. Heavy rainfall leads to increased land-based runoff of pollutants such as nutrients and organic matter from the wetlands. This land-based runoff, together with turbulent sea conditions, leads to conditions that allow for the creation of the sea foam. This is not an uncommon occurrence on Trinidad’s east coast.”
However, the IMA explained that algal blooms are also one common source of thick sea foam.
“When large blooms of algae decay offshore, great amounts of decaying algal matter often wash ashore. Foam forms as this organic matter are churned up by the surf.”
Thankfully, most sea foam is not harmful to humans and is often an indication of a productive ocean ecosystem. But according to the IMA, when large harmful algal blooms decay near shore, it leads to potentially negative impacts on human health and the environment.